The present invention is directed to a signature-handling apparatus. In particular, the present invention relates to an apparatus for transferring signatures between two conveyors which carry signatures.
Typically, signature handling systems include a saddle conveyor which moves signature supports along a path past a plurality of hoppers from which individual signatures are fed. The saddle conveyor conveys the collated group of signatures with their folded edge up to a stitching station where the collated group of signatures is stitched. The signatures are then moved along the path, still with their folded edge up, to a signature transfer station where the signatures are removed from the saddle and moved into a trimmer infeed conveyor. The trimmer infeed conveyor moves the signatures in a direction perpendicular to the saddle conveyor in a plane which is parallel to and above the path of the saddle conveyor. The trimmer infeed conveyor moves the signatures with their folded edge leading.
The transfer of the signatures from the saddle conveyor and into the trimmer infeed conveyor requires not only a change in the direction of movement of the signatures, but also a change in the orientation of the signatures. A conventional method of moving the signatures from the saddle and changing their direction of movement and orientation is shown in U.S. Pat. No. 3,317,026. This patent discloses a mechanism in which the signatures are moved in a step fashion through the stitching station and into a delivery station. A vertically movable blade engages the signature inside the fold of the signature and moves it into the trimmer infeed conveyor. The trimmer infeed conveyor carries the signatures along a path above and transverse to the path of the saddle conveyor. The orientation of the signature is changed so that the folded edge is now leading as it is conveyed by the trimmer infeed conveyor.
The mechanisms for deliverying signatures from the saddle conveyor, such as shown in U.S. Pat. No. 3,317,026, have been satisfactory for collating systems in which signatures are moved in a step fashion, i.e., incrementally, through the stitching station. In such a system, the signatures are stopped when they are stitched and when they are engaged by the vertically moving blade. However, for collating systems where the signature is stapled or stitched while moving, a different delivery mechanism is used.
U.S. Pat. No. 2,998,116 discloses a collating system in which signatures are moved continuously by a saddle conveyor and the signatures are stitched "on the fly", that is, while the signatures are moving. In such a system, transferring the signatures from the saddle becomes somewhat more complicated, because the signatures must be removed from the saddle conveyor while the signatures are moving. In U.S. Pat. No. 2,998,116, a reciprocating blade lifts the signatures from the saddle conveyor and moves the signatures obliquely relative to the saddle conveyor into a series of rollers which continue the oblique movement of the signatures and feed the signatures into a trimmer infeed conveyor.